Abstract

The purposes of this study were to assess V02max and submaximal endurance time to exhaustion (ET) during acute cold-air exposure. Eight male subjects (X age = 19.9 yr) were alternately exposed in groups of four to chamber temperatures of +20 degrees C and -20 degrees C for 30 h each. A week was allowed between exposures. Maximum oxygen uptake was measured using a mechanically- braked cycle ergometer, and ET was determined on the same ergometer using a 17-min/ 3-min exercise/rest schedule until the subject was unable to maintain pedal rate. Maximum oxygen uptake was not significantly different between conditions: 3.43 +/- 0.09 l/min at +20 degrees and 3.35 +/- 0.10 l/min at -20 degrees C. During endurance exercise, intensities equaled 77.1 +/- 1.4 and 78.9 +/2.0 of V02max at +20 degrees C and -20 degrees C., respectively. Heart rate and V02 values obtained between 8 and 10 min of the endurance run were not significantly different. Endurance time to exhaustion however, decreased 38 from 111.9 +/- 22.8 min at +20 degrees C to 66.9 +/- 13.6 min at -20 degrees C. The data support the contention that aerobic capacity is not altered by cold exposure but suggest a marked decrease in submaximal endurance performance. Verf.-Referat